Trees for a 3-valued logic

Abstract

Johnson claims that Slater is mistaken in identifying his system, presented by using tree rules, with a natural deduction system that results from modifying a system used by Copi. He then modifies Slater's tree rules and shows that these tree rules can be used to pick out precisely those arguments that are valid in a three-valued logic described by Bochvar.

Publisher version: http://www.jstor.org/stable/3327454.